1. Field of the Invention
The present invention relates to a lattice boom type crane.
2. Description of the Related Art
On the left and right sides of an upper rotating body of a crawler crane, various types of equipment are provided. Since the space (width) occupied by the equipment is predetermined, the remaining space (width) is used for disposing a gantry. The distance from the right end of the upper rotating body to the center line A of the gantry is obtained from e1+d, wherein e1 is the width occupied by the equipment on the right side (e2 is the width occupied by the equipment on the left side), and d is half of the remainder.
Since the center line B of the boom corresponds with the center line A of the gantry, the determination of the width g of the cabin automatically determines the distance f1 between the boom feet to be (e1+d−g)×2.
Therefore, the distance f1 between the boom feet is restricted, so the load supporting ability of the boom cannot be improved and the weight of the boom cannot be reduced.